Fuel Temperature Sensor 1 - Voltage Above Normal
The fuel temperature sensor is reporting a high voltage reading.
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What it means (plain English)
The fuel temperature sensor measures how hot the diesel fuel is. If it sends a high voltage signal, it might think the fuel is too hot or there's an electrical problem.
What the computer is actually seeing
The engine control module (ECM) sees a voltage reading from the fuel temperature sensor that exceeds the expected range, usually above 4.5V.
What a healthy reading looks like
Normal output voltage from the fuel temperature sensor should be between 0.5V and 4.5V at operating temperatures, depending on design.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors to the fuel temperature sensor for damage or loose connections. If found, repair as necessary. Decision: Is wiring/connectors okay? (Yes: go to step 2, No: repair and retest)
- 22. Measure the voltage output of the fuel temperature sensor with the key on, engine off. Expected range is 0.5V to 4.5V. Decision: Is the sensor output within range? (Yes: go to step 3, No: replace the sensor)
- 33. Check for any software updates or fault codes in the ECM that may relate to the fuel temperature sensor. Decision: Are there ECM issues or updates? (Yes: follow manufacturer's recommendations, No: possible sensor issue)
Common causes
- Damaged wiring or connectors to the fuel temperature sensor
- Faulty fuel temperature sensor
- ECM software glitch
Typical repair cost
$$
Related codes
Frequently asked questions
Can I drive with this code active?
Yes, but fix it soon as it affects performance and injection timing.
Will this code come back after I clear it?
Not if the underlying issue is fixed; if not, it likely will.
Does this code relate to fuel quality issues?
Not directly, but extreme temperatures could indicate other fuel system problems.
Working a real vehicle right now?
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